Forklift trucks of the type adapted to be transported on a carrying vehicle, commonly referred to as piggy-back forklifts, are necessarily of light-weight construction. This is due to the fact that any increase in the weight of the forklift has the direct effect of reducing the carrying capacity of the carrying vehicle. Furthermore, any increase in weight of the piggy-back forklift puts additional strain on the fork tines and any other mounting equipment when the forklift is mounted on the carrying vehicle. Due to the light-weight nature of the forklifts, there is a tendency of the piggy-back forklifts to overbalance when attempting to maneuver heavy goods at or near maximum reach of the forklift. For example, when the forklift is used to load or unload heavy goods to the far side of an elevated platform, such as a trailer bed, at or near maximum reach there is a tendency for the piggy-back forklift to topple forwards against the platform until the mast of the piggy-back forklift abuts against the platform. This is highly undesirable as it may cause irreparable damage to the mast caused by the impact and furthermore can hinder the loading or unloading of goods by preventing either side shift or tilt operations of the mast which are normally needed for correct handling of the goods. In other constructions of forklift trucks, this problem would be overcome simply by adding more weight to the rear of the forklift, but this is simply not feasible for piggy-back forklift trucks.
Various mechanisms have been provided to facilitate the loading and unloading of goods on a raised platform by a piggy-back forklift at or near maximum reach, however, although many of these have certain benefits, generally speaking they do not allow the piggy-back forklift to be operated in the manner that was intended. One forklift loading support that overcomes many of the difficulties with the known types of forklift loading support is described in the Applicants' own published European Patent Application, EP 1 457 456, the entire disclosure of which and in particular the description concerning the loading and unloading of goods from the far side of a trailer is incorporated herein by way of reference. EP 1 457 456 describes a number of constructions of forklift loading support mounted on the side bar of the chassis that facilitate loading and unloading of goods from an elevated platform at or near maximum reach of the piggy-back forklift. There are however problems with the constructions of forklift loading support described therein.
First of all, one construction of loading support described in EP 1 457 456 requires modification of the mounting arrangement of the forklift on the carrying truck in certain instances which is undesirable. Secondly, where the load rest support is permanently mounted adjacent the front of the side bar, extra care and attention must be paid by the operator of the forklift truck when loading the forklift onto the rear of a carrying vehicle so that no damage is caused to the load rest supports. This slows down the process of loading and unloading a piggy-back forklift onto the carrying vehicle. Furthermore, the load rest supports are relatively exposed and can be scraped, or even distorted as a result of an impact caused during loading or unloading of the forklift on the carrying vehicle, which can damage the load rest supports and hinder their subsequent operation as well as hinder subsequent loading or unloading of the piggy-back forklift on the carrying vehicle.
The other main construction of load rest support described in EP 1 457 456 requires the use of locking pins for storing the rest support in an upright position when not in use. These are quite cumbersome and time-consuming for the operator of the piggy-back forklift to manipulate which further increases the time needed to load and unload the piggy-back forklift onto a carrying vehicle. Finally, for both constructions of load rest support shown, it can take a significant amount of time to manipulate the load rest support to and from an operating platform engaging position and a stowed position which is undesirable.